1. Field of the Invention
The present invention relates generally to magnetic heads, methods of manufacturing the same, and magnetic disk units, and more particularly to a magnetic head of low flying height, a method of manufacturing the same, and a magnetic disk unit using the same.
2. Description of the Related Art
In these years, increases in recording densities of magnetic disk units have made the distance (separation distance) between the head slider of a magnetic head and a magnetic disk at the time of recording and reproduction extremely small. This is because as a bit (the minimum unit of a magnetization area) formed in the magnetic disk becomes smaller in size, a signal magnetic field leaking from the bit decreases so that the spatial range of leakage of the signal magnetic field is narrowed. The distance between the head slider and the magnetic disk, or flying height, is 10 nm or less.
FIG. 1 is a schematic diagram showing a conventional magnetic head 200. Referring to FIG. 1, a head slider 201 of the magnetic head 200 has air bearing surfaces (ABSs) 202a and 202b forming air bearings, and a groove part 203 provided on its medium opposing surface, or the surface opposing a magnetic disk 210. The head slider 201 performs recording and reproducing in an element part 204 while maintaining an extremely low flying height, balancing using a pressure (lifting force) due to incoming airflow and a spring force from a flexure (not graphically illustrated) supporting the head slider 201.
In this condition of extremely low flying height, if there is a fine particle 215 on the surface of the magnetic disk 210, the ABSs 202a and 202b of the head slider 201 get on the particle 215, so that the head slider 201 is off balance to be displaced from the flying position. In this case, a protection film 205 such as a carbon film or a carbon hydride film is formed on each of the ABSs 202a and 202b, and a similar protection film 212 of a carbon film is also formed on the surface of the magnetic disk 210. Therefore, as is often the case, no damage is caused by the contact of the ABS 202a or 202b with the protection film 212 of the magnetic disk 210. Reference may be made to Japanese Laid-Open Patent Application No. 2002-133632 for related art.
As shown in FIG. 1, however, in the condition of extremely low flying height, the periphery of the head slider 201, for example, an air outgoing end 201TR of the groove part 203 indicated by the arrow, may come into contact with the surface of the protection film 212 of the magnetic disk 210 when the head slider 201 is off balance to be displaced from the flying position. Composite ceramic of aluminum oxide and titanium carbide is used for the head slider 201, and unevenness resulting from ceramic particles is formed on the surface of the head slider 201. This ceramic is harder than the carbon film. The ceramic is exposed in the groove part 203 of the head slider 201. Therefore, not only the protection film 212 is damaged but also even a recording layer 211 of the magnetic disk 210 may be damaged by the contact with the ceramic. This causes a so-called hard error, that is, error from which it is difficult to recover.